Oviparous animals are those that reproduce by laying eggs. They include animals like birds, most reptiles, most amphibians, most fishes.

Viviparous animals are the animals that give birth directly to their kind. These individuals grow up and live. Oviparous animals are animals that do not give birth to their kind. Instead, they lay eggs that are either fertilised or unfertilised.

Ovoviviparous means producing eggs that hatch inside the mother's body, rather than being laid outside. It's a reproductive strategy that's seen in some fishes and reptiles.